Aerobic exercise is a popular form of exercise that improves one's cardiovascular health by reducing blood pressure and providing other benefits to the human body. Aerobic exercise generally involves low intensity physical exertion over a long duration of time. Typically, the human body can adequately supply enough oxygen to meet the body's demands at the intensity levels involved with aerobic exercise. Popular forms of aerobic exercise include running, jogging, swimming, and cycling among other types of aerobic exercise. In contrast, anaerobic exercise typically involves high intensity exercises over a short duration of time. Popular forms of aerobic exercise include strength training and short distance running
Many choose to perform aerobic exercises indoors, such as in a gym or their home. Often, a user will use an aerobic exercise machine to have an aerobic workout indoors. One such type of aerobic exercise machine is an elliptical exercise machine, which often includes foot supports that move in reciprocating directions when moved by the feet of a user. Often, the foot supports will be mechanically linked to arm levers that can be held by the user during the workout. The arm levers and foot supports move together and collectively provide resistance against the user's motion during the user's workout. Other popular exercise machines that allow a user to perform aerobic exercises indoors include treadmills, rowing machines, stepper machines, and stationary bikes to name a few.
One type of elliptical exercise machine is disclosed in U.S. Pat. No. 6,569,061 issued to Kenneth W. Sterns, et al. This reference describes an exercise apparatus with a frame, left and right leg members pivotally mounted on the frame, and left and right handlebars pivotally mounted on the frame. Various arrangements are provided to facilitate switching, during leg exercise motion, between a first mode of operation involving commensurate arm exercise motion and leg exercise motion, and a second mode of operation involving leg exercise motion without commensurate arm exercise motion. Other types of elliptical exercise machines are described in U.S. Pat. No. 7,871,356 issued to Charles Smith and U.S. Pat. No. 6,485,395 also issued to Kenneth W. Sterns, et al. Each of these references are herein incorporated by reference for all that they contain.